raindancewx

Make it happen Chinook. You guys in Colorado will get at least some snow out of this Thu-Sat period.

The 12-km NAM, Euro, GFS and Canadian now have a pretty big precipitation event out here 12/10-12/12, in the correct time frame after the big SOI crash around 12/1. 3 Dec 2020 1013.45 1007.55 11.31 8.63 7.78 2 Dec 2020 1014.81 1008.05 15.78 8.74 7.73 1 Dec 2020 1014.91 1007.10 21.23 8.99 7.70 30 Nov 2020 1013.51 1006.20 28.18 9.24 7.69 This map from WPC looks pretty good to me. I'd go 0.20-0.60" for most of New Mexico, higher mountains and SW, lower SE (nothing to 0.20"). Arizona could easily get a winter of precipitation in the SE part of the state. This is what the Euro has for days 2-4 (Thursday-Saturday). For a lot of places in the SE AZ / SW NM zone, these totals would be a winter of precipitation if they verified. The 12-km NAM is a lot more optimistic, but I don't really buy these totals, yet.

That's probably the most moisture I've seen a model show in Arizona in at least six months. Not thrilled to see the Euro changing the location of the moisture every 12 hours, but the trend in increasing moisture is nice to see. A lot of it will likely be snow.

I am pretty optimistic for you guys for March. My NAO indicator seems to have worked at least a little bit for December, with the index at least nominally negative. I think the blend I had said -0.2 for December. It had March more negative than December. Nino 4 has been following 2007 (but warmer) all year. If it continues to do that, you do have a strong wet signal for the Ohio Valley in February, and then a weak wet signal for New England. Should still be cold enough for a lot of snow. Nino 4 is likely to finish Dec/Jan the coldest it has been in 5-10 years, maybe more. The warm signal from a cold Nino 4 January doesn't really extend into all of New England either in February. It took until Dec/Jan but the 2007-08 La Nina did see Nino 4 eventually drop below 27.0C, which is very cold for that area, even by 1951-2010 averages. It should happen in the next six weeks. You'll know the effect has kicked in if you see a big snowstorm in say, Kentucky, in mid-January or February. Also a cold signal for you guys in Spring. The correlations aren't super strong, but with Nino 4 set to run ~2C colder in the next few months compared to last year, it should have a big imprint on the patterns. We're not getting jack out here once the Spring correlations kick in, winter is less of an issue though

We're open for business for your skiing and snow needs.

The GFS run from Tuesday was honestly better for this time frame than runs of the recent days. This is the most recent five day period depiction on the GFS and the Canadian: The Canadian is probably too optimistic but I like to use it as a "bust up" ceiling for the high end of what is possible. A lot of this is Thursday-Saturday, so not exactly in la-la model land anymore, but the details are still going to change.

I'm a bit surprised there hasn't been more snow in the red circled area. That's my guess for the next area to fill in a lot.

Nino1+2 Nino3 Nino34 Nino4 Week SST SSTA SST SSTA SST SSTA SST SSTA 07OCT2020 19.5-1.2 23.4-1.5 25.5-1.2 27.8-0.8 14OCT2020 19.6-1.2 23.6-1.3 25.3-1.4 27.8-0.9 21OCT2020 19.9-1.1 23.8-1.2 25.3-1.4 27.8-0.8 28OCT2020 20.0-1.1 23.5-1.5 24.9-1.7 27.9-0.7 04NOV2020 20.3-1.0 23.6-1.3 25.1-1.5 27.8-0.8 11NOV2020 21.2-0.3 24.1-0.9 25.7-1.0 27.9-0.7 18NOV2020 21.0-0.7 23.6-1.4 25.2-1.5 27.9-0.7 25NOV2020 21.0-1.0 23.7-1.3 25.3-1.3 27.9-0.7 02DEC2020 21.8-0.5 24.4-0.7 25.5-1.1 27.6-1.0 We're going to a Modoki La Nina event if the structure of this week keeps up. You have Nino 4 likely to take over as the coldest zone by anomaly as soon as the next few weeks, as Nino 1.2/3/3.4 warm (probably aren't really as weak as this week on a monthly basis though). If you look at early Dec 1997, there is at least a passing resemblance to the early Dec 2020 look in the US, with Nino 1.2 much warmer (relatively) than the western zones.

GFS and Canadian are different, but the NAM looks like the Euro to some degree. The northern stream system is more of a mess at this point, but still expect some snow for Colorado.

You're the one who has been expecting an east-based La Nina. Good luck with that. Trends have been running opposite for weeks now. The plume moves from majority -0.5C or lower through March, to majority above -0.5C in April. That's the end of the La Nina on the Euro. Whether it's fast by a month, or slow by a month, doesn't really matter. I had the event peaking in Nov/Dec at the surface, Oct/Nov at the subsurface, that's still at least possible.

Once the system is over the waters west of Los Angeles and the models see how much moisture it has, I think you'll see rapid re-conciliation toward one solution. Curious to see what the Euro has in a few minutes though. The members above, 2,3,5,10,11,19 seem about right in terms of that "SOI rule" I use. Actually think the ICON has about the right idea on the last run, it goes to the Gulf of California, crosses SE Arizona, runs north north east, loses a lot of moisture, but western NM, SW Colorado get good moisture - rain and snow, southern NM gets rain. Then another system comes in with snow but less moisture.

From 1931-32 to 2019-20 there is no year in Philadelphia over 30 inches of snow (Oct-May basis) if it doesn't snow by 12/20. GFS currently has nothing through 12/20. The average for years with a first snow after 12/20 is 14.5 for Philadelphia. My outlook back in October assumed La Nina would peak in November or December - that still looks right to me. Nino 4 should be the coldest zone in January, given the warming forecast in 1.2, 3, 3.4 while Nino 4 cools longer. The model has essentially a Modoki La Nina for a brief period. A cold Nino 4 in January (say -1.0C) would be a strong wet signal for Ohio, Michigan, Kentucky and Indiana. Even though the south is strongly favored for warmth.

Euro says this La Nina ends in March in Nino 3.4. Nino 4 will continue to strengthen into January, but it thinks Nino 3.4 is done.

You jinxed it. One for me - One for Colorado. (I really think the models may try to phase these somewhere).

It looks like Logan has gone over to snow at 33 degrees in the past half hour or so.

Warm, wet and stormy has been the idea for December for a while now. Keep the snow mostly north of New York City like I had in my outlook, and I'll be happy. Further north you go, the more you get generally, not just overall, but relative to averages. That's been the idea for a while. NAO has gone negative btw -

The 12/10-12/12 periods needs to be watched. The GFS, Canadian, Euro all at least have precipitation for NM and CO in that time frame.

We've now had multiple instances since October where Boston and north do well for snow despite a generally warm pattern. That was one of the ideas in my outlook for the northeast. The 'normal' line for snow should remains between NYC & Boston if I did it right. I know in 2007-08, snow totals were not that good for NYC and Philly and south, but pretty solid for New England. All that said, Boston itself hasn't had a flake of snow just yet at the official site (as of 3 pm) with the current system. I'm sure parts of the Southwest will finish very dry for winter, but I'm still not convinced northern New Mexico, north TX, and southern Colorado will be that dry. The GFS has also been trending this feature north with subtropical origins. There were substantial SOI crashes around 12/1 which usually precedes a storm or subtropical impulse over the SW in 10 days. Some hint of a northern stream feature with some moisture in the 12/10 to 12/12 time frame too.

CPC really isn't that optimistic on a cold look for the northern United States through mid-month, and it's already warm in those areas generally. They have warmth building even into the South too. My outlook didn't have the NE that warm, and even in the Southeast I wasn't super hot in December, generally +2 to +4 South, and +1 to +3 north. Will be curious to see how these do.

2007 and 2020 have been very similar all year on the western side of the La Nina. Don't really see that changing anytime. The CPC had Nino 3.4 at 25.31C (-1.19C v. 1951-2010, but much colder for the last 30 years) and Nino 4 as 27.85C (-0.54C v. 1951-2010, but much colder for the last 30 years). The ( ) includes the 60-year anomaly in Nov with the recent stronger La Ninas since 2000. Nov 1.2 3 3.4 4 2007 19.92C (-1.51C) 23.48C (-1.37C) 25.17C (-1.32C) 27.61C (-0.78C) 2010 20.34C (-1.09C) 23.59C (-1.26C) 25.06C (-1.43C) 27.11C (-1.28C) 2011 21.09C (-0.34C) 23.98C (-0.87C) 25.52C (-0.97C) 27.80C (-0.59C) 2020 20.86C (-0.57C) 23.88C (-0.97C) 25.31C (-1.18C) 27.85C (-0.54C) A blend of 2007/2011 is pretty close for the four zones in November: 20.50C / 23.70C / 25.35C / 27.70C Both 2007/2011 had +NAO looks too. I'd call the November La Nina look "central" looking as opposed to basin-wide (2010), east based or west based since Nino 4 and Nino 1.2 are nothing special.

QBO rose to +11 in November. 2020 -2.51 -3.20 -4.36 -5.03 -4.86 -2.78 0.34 4.78 7.95 10.80 11.15 -999.00 Still think is the decent blend. The QBO really doesn't get much higher than it is now, but it misbehaved to get here (really should be negative), so maybe we'll bust through that +16 barrier this year. Doubt it though. Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 1961 -5.47 -0.62 0.54 2.82 6.88 7.96 6.69 5.60 6.02 7.59 8.74 2010 -16.02 -16.98 -19.68 -23.57 -26.28 -25.05 -9.84 1.45 6.58 10.83 12.16 2016 9.34 6.77 3.16 0.64 2.37 3.86 6.25 10.07 10.48 12.83 14.16 2016 9.34 6.77 3.16 0.64 2.37 3.86 6.25 10.07 10.48 12.83 14.16 2016 9.34 6.77 3.16 0.64 2.37 3.86 6.25 10.07 10.48 12.83 14.16 Blend 1.31 0.54 -1.93 -3.77 -2.46 -1.10 3.12 7.45 8.81 11.38 12.68 2020 -2.51 -3.20 -4.36 -5.03 -4.86 -2.78 0.34 4.78 7.95 10.80 11.15 Trend down down down up up up up up up up Timing wise, 2016 is still a better match than 2010 in terms of the East (-)/West (+) QBO positioning and trend.

This is roughly how we're doing locally - A lot more snow for the northern and western areas of town today. I had a dusting, the official site had nothing. I was at 7.5 inches with the October snow before the final inch or so came in and I couldn't measure it since I had to drive to work. But probably close to 9 inches at my place this season. Average for this part of town is around 11 inches.

The northern oceans aren't a bad match to 2013, but there are still a lot of issues with that year. The La Nina, solar activity, the Summer/Fall progression for US weather, the two hurricane seasons are completely different, sea ice extent is far lower, and 2020 follows several warm ENSO years while 2013 follows several cold ENSO years. Can't really see blob similarities over riding all of those differences.

I'm aware of the research, but it's more of an Eastern New Mexico and east thing than for the Rio Grande Valley where I am. We do get a lot of surprisingly bad large hail events in New Mexico. I've had to get my roof and windshield fixed from hail damage several times in the past decade. The SOI crash from 10 days ago (11/21-11/23) more of less verified here with widespread light snow bands over Northern New Mexico. Missed the airport, but I had a dusting. Some areas of town had four inches or so. This is the West Side of Albuquerque. North of town in Rio Rancho A lot of the mountain ski resorts should be fine when they open. I know Taos and some of the other resorts have a good base of mostly natural snow. At 11,000 feet up, the Taos Powderhorn mountain observations showed 26 inches of snow pack today, very similar to the strong Fall starts in 2013, 2015, 2018 and 2019, all 25-29 inches. I mention the snow for a couple reasons. The La Nina snow signal is "bad" - usually in the entire Southwest. But just about all of New Mexico is running well above average. The West Side of Albuquerque had 8-14" in October, with 2-4" with this storm. They average less than the airport (9.6"), more like 6 inches. Where I am, it's more like 4-8" in October, 0-1" with the current system, and the average is closer to 12" or so. Santa Fe had 1" in September, 4-8" in October, 1-3" in November, and now 2-4" in December against 22" or so long-term. So a lot of places are already nearing their annual snow averages. In the mountainous areas, towns like Chama and Red River get well over 100 inches with good long-term records and are at least 30-35% of the way to their final averages already, even though they'll keep seeing snow into May most years. I find New Mexico does well in La Ninas when they stop developing or start to weaken, but also about 1/3 of La Ninas that are average to good for snow here: 1970, 1971, 1973, 1974, 1983, 1984, 1988, 2000, 2011, 2016. I'm looking at those years more lately, a lot more than the one third of very bad La Ninas out here (1933, 1950, 1955, 1975, 1995, 1999, 2005, 2008, 2017). The 1981-2010 baseline is ~26.75C, so the 1.4C depicted here implies 25.35 or so November. We'll see what the CPC reading is when ONI updates this week. For 1951-2010, the November average is 26.5C - so this event is still not that strong by historical standards. It's much more 2011 than 2010 right now. My winter forecast assumed a 25.5C La Nina overall for Dec-Feb, with Dec coldest of the three months by raw SSTs and Feb warmest. Looks OK so far. Generally, the La Ninas with a warmer Nino 1.2 relative to 3/3.4/4 are better here. So the depiction of the Canadian (shifting West) matches with the observations that this event is not really East based despite what DT and some of the other forecasts I've seen imply. The European initialization has even Nino 4 colder than Nino 1.2, for the actual winter, both were -0.8C for November. I've liked 2007 for a while because it started east-based in early Fall, but ended up coldest in Nino 4 for a while late winter and spring. You can compare the structure to 2017-18, when you had Nino 1.2 go near 0 to -1.5 in December - way colder than the other zones. The current event is far more likely to see additional cooling in Nino 4 while Nino 1.2 warms a lot.

The airport of course got literally nothing. But areas north and west of it in the metro did very well overnight. So that SOI crash from 11/21-11/23 did well here. I had a dusting.